3-Chlorostyrylcaffeine

3-Chlorostyrylcaffeine (CSC), or 8-(3-chlorostyryl)caffeine (8-CSC), is a potent and selective adenosine A_2A receptor antagonist which is used in scientific research.^[1][2]

Other namesCSC; 8-CSC; 8-(3-Chlorostyryl)caffeine; 8-(3-Chlorostyryl)-1,3,7-trimethylxanthine

Drug classAdenosine A_2A receptor antagonist

CAS Number

• 147700-11-6 ^Y

PubChem CID

• 129730232

Quick facts Clinical data, Other names ...

3-Chlorostyrylcaffeine

Clinical data
Other names	CSC; 8-CSC; 8-(3-Chlorostyryl)caffeine; 8-(3-Chlorostyryl)-1,3,7-trimethylxanthine
Drug class	Adenosine A2A receptor antagonist
Identifiers
IUPAC name 1-[3-(3-chlorophenyl)prop-2-enyl]-3,7-dimethylpurine-2,6-dione
CAS Number	147700-11-6 Y
PubChem CID	129730232
ChemSpider	4510063
Chemical and physical data
Formula	C16H15ClN4O2
Molar mass	330.77 g·mol−1
3D model (JSmol)	Interactive image
SMILES CN1C=NC2=C1C(=O)N(C(=O)N2C)CC=CC3=CC(=CC=C3)Cl
InChI InChI=1S/C16H15ClN4O2/c1-19-10-18-14-13(19)15(22)21(16(23)20(14)2)8-4-6-11-5-3-7-12(17)9-11/h3-7,9-10H,8H2,1-2H3 Key:VYLMWABBINHTEH-UHFFFAOYSA-N

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It has 520-fold selectivity for the adenosine A_2A receptor over the adenosine A₁ receptor (K_i = 54 nM and 28,000 nM for the rat receptors, respectively).^[1][2] Its affinities for the adenosine A_2B and A₃ receptors are similarly low (K_i = 8,200 nM and >10,000 nM, respectively).^[3]

CSC has been found to reverse the catalepsy induced by the dopamine D₁ receptor antagonist SCH-23390 and the dopamine D₂ receptor antagonists raclopride and sulpiride in animals.^[4][5][6]

The drug was one of the first selective adenosine A_2A receptor antagonists to be developed.^[1] However, in addition to its adenosine receptor antagonism, CSC was subsequently found to be a potent monoamine oxidase B (MAO-B) inhibitor (K_i = 80.6 nM for baboon MAO-B).^{[2][1][3][7][8]} CSC was first described in the scientific literature by 1993.^[9]